Recently, hydrogen fuel energy has been emerged as substitute energy source of fossil fuel, since the hydrogen fuel energy can be regenerated unlimitedly and does not produce environment pollution. Thus, research into storing and controlling hydrogen fuel energy has been actively conducted in various fields such as production technologies, storage technologies, and transportation and movement technologies. In particular, research into hydrogen fuel cell vehicles using hydrogen fuel energy have been on the rise.
Meanwhile, hydrogen fuel or hydrogen gas has a possibility of being ignited and exploded when concentration thereof in the air is greater than about 4% (vol/vol), and thus, a highly sensitive hydrogen sensor that can rapidly and accurately detect leakage of hydrogen gas may be considered as a core technology for commercialization of hydrogen fuel energy in various technical fields utilizing hydrogen fuel energy.
Conventionally, equipment of detecting hydrogen gas using catalytic, electrochemical, and mechanical factors, and principles related to acoustic waves, heat conductivity, change in resistance, and work functions has been used. However, the conventional detection equipment may be mostly large in size, high in price, and has a limitation in movement and application fields, and further, detection operation thereof may be performed at high risk in an environment with an explosion possibility.
In order to solve the above mentioned problem, a sensor employing an optical hydrogen detection scheme has been proposed. The sensor based on the optical hydrogen detection scheme may be available for remote detection using an optical cable and may not require an electric circuit in a detection region, thereby providing high stability. However, such a sensor based on the optical hydrogen detection scheme may use high-priced materials, thereby increasing manufacturing cost, and its corrosion due to oxygen and moisture in the air may cause degradation of sensitivity and shorten a lifespan.
Thus, a technique is demanded for manufacturing a highly efficient and stable hydrogen detection sensor that may be extensively used in the various industries, can be detectable by naked eyes, can be manufactured easily at reduced cost in a manufacturing process, and may not be degraded in sensitivity.